Fiber optic connectors having a ferrule insertion stop

ABSTRACT

A ferrule-based fiber optic connectors having a connector assembly with a ferrule insertion stop for limiting the insertion of a ferrule into a ferrule sleeve are disclosed. In one embodiment, the fiber optic connector comprising a connector assembly, ferrule insertion stop, a connector sleeve assembly and a female coupling housing. The connector assembly comprises a ferrule and a resilient member for biasing the ferrule forward and the connector sleeve assembly comprises a housing and a ferrule sleeve, where the ferrule of the connector assembly is at least partially disposed in the ferrule sleeve when assembled. The ferrule insertion stop limits the depth that the ferrule may be inserted into the ferrule sleeve.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of International Application No.PCT/US17/21766, filed on Mar. 10, 2017, which claims the benefit ofpriority to U.S. Provisional Application No. 62/306,377, filed on Mar.10, 2016, the content of which is relied upon and incorporated herein byreference.

BACKGROUND

The disclosure is directed to fiber optic connectors having atranslatable ferrule with one or more optical fibers along with cableassemblies using the fiber optic connectors. More specifically, thedisclosure is directed to ferrule-based fiber optic connectors having abalanced ferrule retraction characteristic for preserving opticalperformance.

Optical fiber is increasingly being used for a variety of applications,including but not limited to broadband voice, video, and datatransmission. As bandwidth demands increase optical fiber is migratingtoward subscribers in outdoor communication networks such as in fiber tothe premises applications such as FTTx and the like. To address thisneed for making optical connections in communication networks for theoutside the plant environment hardened fiber optic connectors weredeveloped. One of the most commercially successful hardened fiber opticconnectors is the OptiTap® male plug connector sold by Corning CableSystems, LLC of Hickory, N.C., such as disclosed in U.S. Pat. Nos.7,090,406 and 7,113,679 (the '406 and '679 patents) and incorporatedherein by reference. The Optitap® connector is a hardened male plugconnector for terminating a cable that is configured for opticalconnection using a receptacle. As used herein, the term “hardened”describes a connector or receptacle port intended for making anenvironmentally sealed optical connection suitable for outdoor use, andthe term “non-hardened” describes a connector or receptacle port that isnot intended for making an environmentally sealed optical connectionsuch as a SC connector.

FIGS. 1A-1C are prior art depictions showing various stages of mating ofa preconnectorized cable 10 having a plug connector 5 such as anOptiTap® connector with a receptacle 30. Receptacle 30 mates plugconnector 5 with a standard SC connector (i.e., a non-hardenedconnector) at a second end (not visible in these views) using an adaptersleeve for aligning ferrules when mating plug connector 5 with the anon-hardened connector. Protection of the non-hardened connector side ofthe receptacle is typically accomplished by mounting the receptacle 30through a wall of an enclosure or the like so that the non-hardened endof the receptacle is disposed inside the enclosure for environmentalprotection of the non-hardened connector. As shown by FIGS. 1A-1C, theother end of the receptacle 30 is accessible for receiving the plugconnector 5 at the wall of the enclosure. Other applications may mountthe receptacle 30 inside an enclosure on a bracket or the like.

Receptacle 30 allows an optical connection between the hardenedconnector such as the OptiTap® male plug connector with a non-hardenedconnector such as the SC connector at nodes in the optical network thattypically transition from an outdoor space to an indoor space. FIG. 2depicts an exploded view of receptacle 30, which is described in furtherdetail in U.S. Pat. No. 6,579,014. As depicted, receptacle 30 includes areceptacle housing 12 and an adapter sleeve 18 disposed therein. Thereceptacle 30 receives a non-hardened connector at a second end 16 asrepresented by the arrow pointing to the left Adapter sleeve 18 isbiased toward a first end 14 of the receptacle 30 that receives theconnector 5 using springs 38. This biasing of the adapter sleeve 18toward the first end 14 that receives the plug connector 5 is used formaintaining physical ferrule-to-ferrule contact between the plugconnector and the SC connector to increase the “float” between themating ferrules. When mated, the ferrule of the plug connector 5 is notlatched to the adapter sleeve and springs 38 of receptacle 30 are usedfor increasing the “float” between the mating ferrules of the plugconnector and the non-hardened connector and is used because.

Network operators often desire to optically connect a first hardenedconnector to another hardened connector in a space that requires arugged connection point, which receptacle 30 is incapable ofaccomplishing. Consequently, there exists an unresolved need for fiberoptic connectors that can mate directly with to another hardenedconnector in a quick and reliable manner while providing a ruggedizedsolution that preserves optical performance.

SUMMARY

The disclosure is directed to ferrule-based fiber optic connectorscomprising a ferrule insertion stop for inhibiting the loading-up of theferrule displacement within one of the fiber optic connectors, which cancause undue optical attenuation when mated with a complimentaryconnector. The concepts disclosed are useful for hardened fiber opticconnectors that mate directly to hardened plug connectors, but may alsobe used with other types of connectors as desired. As an example theconcepts are useful with a female hardened connector that mates with ahardened plug connector, but other applications for the conceptsdisclosed are possible and advantageous as well. Thus, the conceptsdisclosed also allow a compact footprint and reliable performance forfiber optic connectors.

One aspect of the disclosure is directed to a fiber optic connectorcomprising a connector assembly comprising a housing, a ferrule and aresilient member for biasing the ferrule forward, along with a ferruleinsertion stop disposed about a portion of the ferrule, a first shell, asecond shell, a connector sleeve assembly and a female coupling housing.The connector sleeve assembly comprises a housing comprising one or morefeatures configured for attaching to the connector assembly and apassageway between a first end and a second end along with a ferrulesleeve. When assembled, the ferrule of the connector assembly is atleast partially disposed in the ferrule sleeve. The female couplinghousing comprises an opening for receiving a complimentary connector.Consequently, the fiber optic connector may be mated directly withanother connector without the use of a third assembly.

Another aspect of the disclosure is directed to a fiber optic connectorcomprising a connector assembly comprising a housing, a ferrule and aresilient member for biasing the ferrule forward, along with a ferruleinsertion stop disposed about a portion of the ferrule, a first shell, asecond shell, a connector sleeve assembly and a female coupling housing.In this embodiment, the ferrule insertion stop is a collar disposedabout a portion of the ferrule. The connector sleeve assembly comprisesa housing comprising one or more features configured for attaching tothe connector assembly and a passageway between a first end and a secondend along with a ferrule sleeve. When assembled, the ferrule of theconnector assembly is at least partially disposed in the ferrule sleeve.The female coupling housing comprises an opening for receiving acomplimentary connector.

Still another aspect of the disclosure is directed to a fiber opticconnector comprising a connector assembly comprising a housing, aferrule, a ferrule holder, and a resilient member for biasing theferrule forward, along with a ferrule insertion stop, a first shell, asecond shell, a connector sleeve assembly and a female coupling housing.In this embodiment, the ferrule insertion stop is defined by one or moreextensions formed as a portion of the ferrule holder. The connectorsleeve assembly comprises a housing comprising one or more featuresconfigured for attaching to the connector assembly and a passagewaybetween a first end and a second end along with a ferrule sleeve. Whenassembled, the ferrule of the connector assembly is at least partiallydisposed in the ferrule sleeve. The female coupling housing comprises anopening for receiving a complimentary connector.

Additional features and advantages will be set forth in the detaileddescription which follows, and in part will be readily apparent to thoseskilled in the art from that description or recognized by practicing thesame as described herein, including the detailed description thatfollows, the claims, as well as the appended drawings.

It is to be understood that both the foregoing general description andthe following detailed description present embodiments that are intendedto provide an overview or framework for understanding the nature andcharacter of the claims. The accompanying drawings are included toprovide a further understanding of the disclosure, and are incorporatedinto and constitute a part of this specification. The drawingsillustrate various embodiments and together with the description serveto explain the principles and operation.

BRIEF DESCRIPTION OF THE FIGURES

FIGS. 1A-1C show portions of a conventional preconnectorized fiber dropcable having a hardened connector such as an OptiTapt male plugconnector being inserted into and connected with a conventionalreceptacle for alignment and mating the hardened connector with anon-hardened connector;

FIG. 2 is a partially exploded view of a conventional receptacle such asdepicted in FIGS. 1A-1C for mating a hardened connector with anon-hardened connector;

FIG. 3 is a schematic force-loading diagram for the conventionalreceptacle of 2 with its floating biasing spring construction accordingto the prior art;

FIG. 4 is a perspective view of cable assembly having an explanatoryfiber optic connector according to the concepts disclosed;

FIG. 5 is an exploded view of cable assembly of FIG. 4;

FIG. 6 is an exploded view of the fiber optic connector of FIG. 4;

FIG. 7 is a partial detailed exploded view depicting select componentsof the fiber optic connector of FIG. 4;

FIG. 8 is an exploded view of the connector assembly depicted in FIGS.5-7;

FIGS. 9 and 10 depict the ferrule assembly portion of the connectorassembly of the fiber optic connector of FIG. 4 in exploded andassembled perspective views showing a ferrule insertion stop;

FIG. 11 depicts an exploded view of another ferrule assembly portionhaving an alternative feature insertion stop for a fiber optic connectoraccording to the concepts disclosed herein;

FIGS. 12-14 are perspective views showing the assembly of components forthe fiber optic connector of FIG. 13;

FIG. 15 is a partial sectional view of the assembly of FIG. 14;

FIG. 16 is an end perspective view of the cable assembly of FIG. 4 withthe dust cap removed;

FIG. 17 is a perspective view of the cable assembly of FIG. 4 beingaligned with a complimentary connector for mating;

FIG. 18 is a partially exploded view of another fiber optic connectordesign with a construction that inhibits excessive ferrule displacement;

FIG. 19 is an exploded perspective view of a sub-assembly of theconnector of FIG. 18; and

FIG. 20 is a perspective assembled view of the sub-assembly of theconnector of FIG. 19.

DETAILED DESCRIPTION

Reference will now be made in detail to the embodiments of thedisclosure, examples of which are illustrated in the accompanyingdrawings. Whenever possible, like reference numbers will be used torefer to like components or parts.

The fiber optic connectors and cable assemblies described herein aresuitable for making optical and/or optical-electrical connections (ifelectrical connections are included in the connectors) to a conventionalmale hardened plug connector Although the concepts disclosed herein areexplained with respect to a female hardened fiber optic connector usedfor optical connection with the male hardened plug connector an OptiTapconnector, the concepts disclosed may be used with other fiber opticconnectors hardened or not and are not limited to this particularoptical connection.

The concepts of the disclosure advantageously allow robust and reliableoptical connections for ferrule-based fiber optic connectors by limitingthe ferrule insertion depth into a ferrule sleeve and inhibiting theloading-up of the ferrule displacement in the fiber optic connector thatcan occur during assembly and/or during mating, thereby avoiding undueoptical attenuation. As explained below, the ferrule retraction (i.e.,displacement during mating) in ferrule-based fiber optic connectorsdepend on several factors, but the concepts disclosed inhibit theloading-up of ferrule displacement in the fiber optic connector bylimiting the insertion depth of the ferrule into the ferrule sleeve.

For explanatory purposes, the operation of the prior art receptacle 30of FIG. 2 is explained using a schematic force-loading diagram of FIG.3. FIG. 3 is a schematic force-loading diagram for the conventionalreceptacle 30 of FIG. 2 depicting its “floating biasing spring”construction for mating a hardened connector with a non-hardenedconnector. In the “floating biasing spring” construction of receptacle30 the non-hardened connector 8 floats as a unit with adapter sleeve 18.FIG. 3 depicts a dashed line drawn around the adapter sleeve 18 and thenon-hardened connector 8 and the dashed line represents that the adaptersleeve 18 and non-hardened connector 8 “floating as a unit” within areceptacle housing 12 according to conventional receptacle 30 of theprior art. As shown, springs 38 bias the floating unit toward a firstend 14 of the receptacle 30 that receives the plug connector 5. Thearrow of FIG. 3 pointing to the left represents the insertion directionof the hardened connector such as plug connector 5 being inserted intoreceptacle 30.

The problem with conventional connectors is that, typically, oneconnector assembly having a ferrule is pre-inserted into the connectorsleeve assembly creating a fiber optic connector. Later a matingconnector is inserted into fiber optic connector. Although both of themating connector assemblies of fiber optic connector and the mating plugconnector represented by the arrow are similar, the behavior of theindividual connector assemblies of the plug connector and the fiberoptic connector are not similar during mating. The ceramic basedferrules of fiber optic connectors are axially aligned for physicalcontact during mating using a ferrule sleeve having a precision-fit withthe ferrules that are inserted therein. However, this ferrule sleeve ispositioned within a housing of the connector sleeve assembly so that itis “loosely captive” within the housing. “Loosely captive” means thatthe ferrule sleeve is held within the housing such that it has noimpediment to expanding as a ferrule enters, along with having space toaccommodate variations in the initial mating angle of mating ferrules,and the ferrule sleeve may also move axially. These movements of theferrule sleeve are required to allow alignment and proper mating of theferrule faces for inhibiting undue optical attenuation in the matingconnectors.

There is a friction force between the ceramic ferrule and ferrule sleevethat must be overcome during assembly. Consider the ferrule of the firstfiber optic connector being “prepositioned” within the ferrule sleeve soits endface is disposed about halfway into the length of the ferrulesleeve. The ferrule sleeve being “loosely captive” within the housing is“pushed” during this “prepositioning” to the farthest point within thehousing away from the inserted ferrule (i.e., to the far end where itawaits the complimentary mating ferrule. The ferrule sleeve will notmove on its own from this position due to the static friction forcebetween ferrule sleeve and ferrule of the connector assembly.

When the mating ferrule of the complimentary connector encounters theferrule sleeve of the first fiber optic connector during mating, themating ferrule causes the ferrule sleeve to “open” to receive the matingferrule. Generally speaking, the ferrules sleeve typically has a lead-infeature such as a chamfer to ease this initial transition. Once “open”the mating ferrule may be inserted into the ferrule sleeve until itencounters the ferrule of the first fiber optic connector for physicalcontact during mating. However, it is likely that the matingferrules/ferrule sleeve are displaced from a generally centeredposition, which can cause undue optical attenuation and/or otherperformance issues. For instance, the mating ferrule of the plugconnector may be displaced by a distance than is greater than the designparameters of the plug connector being mated with the first fiber opticconnector. Although the connectors may still be mated, this unevendisplacement of ferrules is undesirable and may cause elevated levels ofoptical attenuation, reduce reliability and/or cause other issues forthe mated connectors.

The present application solves this problem of unbalanced displacementof ferrules during mating by providing fiber optic connectors with aferrule insertion stop as disclosed herein.

FIG. 4 is a perspective view of cable assembly 200 having an explanatoryfiber optic connector 100 (hereinafter “connector”) attached to an endof fiber optic cable 140 (hereinafter “cable”) and FIG. 5 is an explodedview of the cable assembly 200. FIG. 6 is an exploded view of the fiberoptic connector 100 and FIG. 7 is a partial detailed exploded viewdepicting select components of the connector 100. FIG. 4 depictsconnector 100 having a dust cap 168 attached thereto via threads thatcooperate with a female coupling housing 164.

The construction and operation of connector 100 that is very differentthan the construction of receptacle 30 of FIG. 2 when mating to acomplimentary connector. Although the connector depicted is a hardenedfemale connector for receiving a male hardened connector plug such as anOptiTap® connector for a direct optical connection, the concepts may beused with other suitable connectors as desired. The present applicationsolves the issues of excess ferrule displacement within the ferrulesleeve by using a ferrule insertion stop to inhibit issues of excessferrule displacement relative to the ferrule sleeve during assembly andmating.

In one embodiment, connectors having a construction with a ferruleinsertion stop according to the concepts disclosed comprises a connectorassembly 52, a ferrule insertion stop 130 for inhibiting excess ferruledisplacement within the fiber optic connector, and a connector sleeveassembly 136 as depicted in FIG. 5. Specific constructions of connectorsaccording to the concepts disclosed maybe embodied in a variety ofdifferent connector constructions. Moreover, the ferrule insertion stopmay take any suitable form such as a collar (FIGS. 9 and 10) or ferruleholder defining one or more extensions (FIG. 11) to limit the insertiondepth of the ferrule into the ferrule sleeve.

Fiber optic connectors disclosed herein may include any suitableconnector assembly. By way of example, and not limitation, suitableconnector assemblies may include LC, SC along with other connectorassemblies having a ferrule and ferrule sleeve arrangement as desired.As best shown in FIG. 8, connector assembly 52 comprises a connectorhousing 52 a, a ferrule 52 b, and a resilient member 52 c. The connectorassembly 52 depicted is a SC connector assembly that also includes aspring push 52 d and a ferrule holder 52 f Spring push 52 d attaches toa portion of housing 52 a when assembled and allows resilient member 52c to bias the ferrule 52 b (and the ferrule holder 52 f) forward.Connectors disclosed herein are advantageous for efficiently andeconomically streamlining the deployment and installation of fiber opticnetworks since they provide a robust and reliable operation along withdirect connection with a complimentary connector. Moreover, using anindustry standard connector assembly provides a known connectorfootprint for the fiber optic connectors.

As best shown in FIG. 6, connector 100 comprises connector assembly 52,ferrule insertion stop 130, connector sleeve assembly 136, a first shell155 a, a second shell 155 b, and a female coupling housing 164.Connector sleeve assembly 136 comprises a housing 133 and a ferrulesleeve 135. Housing 133 comprises one or more features 133 a configuredfor attaching to connector assembly 52 and a passageway 133 p between afirst end and a second end of the housing 133 as shown in FIG. 7. By wayof example, connector 100 may also comprise a cable adapter 180 and aboot 166. When assembled, the ferrule 52 b of the connector assembly 52is at least partially disposed in the ferrule sleeve 135. Ferruleinsertion stop 130 limits the insertion depth of the ferrule 52 b into aferrule sleeve 135 of the connector sleeve assembly 136 and inhibitsover-insertion of the ferrule, thereby inhibiting undue opticalattenuation of due to excessive ferrule displacement relative to theferrule sleeve 135. Consequently, neither ferrule of the mated ferruleshave an excess displacement within the ferrule sleeve 135 when theoptical connection is made.

Ferrule insertion stop 130 may be any suitable structure that allowsoptical mating of the ferrules within the ferrule sleeve and inhibitsover-insertion of the first ferrule. By way of example, FIGS. 9 and 10depict a first ferrule assembly portion of connector assembly 52 in anexploded and assembled perspective views. As depicted, ferrule holder 52f has a passageway therethrough and is sized for receiving an end offerrule 52 b. In this embodiment, ferrule insertion stop 130 isconfigured as a collar that fits over a portion of ferrule 52 b. Ferruleinsertion stop 130 may have a suitable friction fit with the ferrule 52b or be secured in another suitable manner. The length of the collar issized so that when it abuts the ferrule holder 52 f the desiredinsertion length of the ferrule 52 b is exposed. Although, the collar isdepicted as an annular ring, the ferrule insertion stop could be lessthan an entire ring as desired. FIG. 10 depicts the assembled ferruleassembly with the ferrule insertion stop 130 that acts to limit theinsertion depth of the ferrule 52 b into the ferrule sleeve 135 ofconnector 100 when assembled.

Other suitable structures for the ferrule insertion stop are alsopossible. FIG. 11 depicts an exploded view of another ferrule assemblyportion of connector assembly 52 having an alternative ferrule insertionstop 130′ for connector 100 according to the concepts disclosed herein.In this embodiment, ferrule insertion stop 130′ is a portion of theferrule holder 521. Specifically, the ferrule insertion stop 130′ areone or more extensions formed as a portion of ferrule holder 521. Whenthe ferrule assembly portion is assembled the ferrule insertion stops130′ are disposed about a portion of the ferrule and limit the insertiondepth of the ferrule 52 b into the ferrule sleeve 135 of the connectorsleeve assembly 136. The extensions have a suitable length for allowingthe desired insertion depth of the ferrule 52 b into the ferrule sleeve135. Although, four ferrule insertion stops 130′ are formed in ferruleholder 521, other ferrule holders may have other suitable numbers ofextensions. In still other embodiments, the ferrule insertion stops 130′could be separate components that fit into the ferrule holder.

Still other variations of the ferrule assembly portion of FIG. 11 arepossible. By way of explanation, if the a keying portion of ferruleholder 52 f is omitted then the ferrule insertion stops 130′ may have adual-function for limiting insertion depth and tuning of the ferrule 52b with the connector housing. For instance, if four extensions are usedfor the ferrule insertion stops 130′, then the inner passageway of theconnector housing may include complimentary features for allow fourdifferent rotational positions of the ferrule 52 b relative to theconnector housing, thereby providing a tuning feature for the connectorassembly 52. Of course, other suitable numbers of extensions can providetuning to other rotations positions as desired such as six positions oreight positions.

FIGS. 12-14 are perspective views showing the assembly of components forconnector 100 and FIG. 15 is a partial sectional view of the assembly ofFIG. 14. FIG. 12 is a perspective view depicting cable 140 attached toconnector assembly 52 and positioned in shell 155 b. In this embodiment,cable 140 is secured to connector assembly 52 using a crimp band 170that is attached to a portion of spring push 52 d.

Cable 140 may comprise one or more optical fibers, one or more tensileelements such as strength members or strength components, and a cablejacket, but other suitable components are possible. The tensile elementsof fiber optic cable 140 (not shown) are typically secured to a cableattachment region of connector 100 or connector assembly 52. In thisembodiment, the strength members of cable 140 such as aramid yarns arepositioned about a rear portion of spring push 52 d and secured theretousing crimp band 170. However, cable 140 may be strain-relieved toconnector 100 in other suitable manners. For instance, strength membersor strength components may be secured to the body 155 such as by using acrimp band or an adhesive.

As shown in FIG. 13, connector 100 comprises a body 155 for securing theconnector assembly 52 at a front end of one or more shells. In thisembodiment, body 155 has a first shell 155 a and a second shell 155 bthat form the body 155. Shells 155 a and 155 b may be the same part ornot depending on the desired construction. In this embodiment, shells155 a, 155 b each comprise a latch 155L and a catch 155C for securingthe first and second shells together in a snap-fit construction for easeof assembly. Other configurations for shells 155 a, 155 b are alsopossible such as securing the shells with a crimp band or adhesive asdesired. Connector 100 may also comprise other optionally componentssuch as a cable boot 166, a heat shrink tube 167, a second crimp band,and/or one or more O-rings for sealing. For complexity reduction andsimplification, the connector 100 can use many of the same parts as theOptiTap® plug connector 5 or other standard parts as desired; however,certain components may be specific to connector 100.

By way of explanation other embodiments of body 155 may have the shellssecured with a crimp band that is deformed about an outer barrel portionof the body. Further, the crimp band may also be used for securing thetensile elements of cable 140. For instance, the tensile elements may bea plurality of tensile yarns attached between an outer barrel of body155 and the crimp band. In other embodiments, one or more strengthcomponents such as GRP rods maybe secured to the cable attachment regionof the fiber optic connector such as between the shells 155 a, 155 b.Alternatively, two crimp bands may be used for cables or constructionswhere it is desired to strain-relieve the fiber optic cable directly tothe connector assembly 52 and to the shells. By way of example, tensileelements such as aramid yarns may be secured to the connector assembly52 as discussed herein and the second crimp band 153 is used forstrain-relieving tensile elements to the body 155. Connectors may alsoinclude a dust cap 168, but other suitable configurations are possibleusing fewer or more components. For instance, connector 100 may alsoinclude an optional lanyard (not numbered) for the dust cap 168 asdesired so it is prevented from being lost or separated from theassembly.

Generally speaking, most of the components of fiber optic connector 100are formed from a suitable polymer, but other materials such as metalare possible. In one example, the polymer is a UV stabilized polymersuch as ULTEM 2210 available from GE Plastics if the component isexposed to the elements; however, other suitable polymer materials arepossible. For instance, stainless steel or any other suitable metal maybe used for various components as desired.

FIG. 14 depicts the connector sleeve assembly 136 attached to theconnector assembly 52. The housing 133 of connector sleeve assembly 136may be formed as a single component as shown or formed as an assembly ofmore than one component. In this embodiment, the housing of 133connector sleeve assembly 136 is formed a single component as bestdepicted in FIGS. 5-7, thereby making the features of the connectorsleeve assembly easier to manufacture and assemble. However, theconcepts disclosed herein may be used with any suitable connector sleeveassembly such as housing comprising several components if desired. Asdepicted, housing 133 also includes one or more latch arms 133 a forsecuring the housing 133 with connector assembly 52.

The housing 133 of connector sleeve assembly 136 has a throughpassageway from a first end to a second end for receiving ferrule sleeve135 in a loosely captive manner and aligning respective ferrules of theconnector 100 and the mating connector as discussed herein.Specifically, when assembled, connector sleeve assembly 136 fits withinfemale coupling housing 164 and is used for aligning ferrule 52 b ofconnector 100 with the corresponding ferrule of the plug connector 5.

As best depicted in FIG. 15, ferrule sleeve 135 is disposed withinhousing 133 and the ferrule 52 b of connector assembly 52 is at leastpartially disposed in the ferrule sleeve 135 when assembled. Also asdepicted, the ferrule insertion stop 130 limits the insertion depth offerrule 52 into the ferrule sleeve 135 of the connector sleeve assembly.

In addition to the connector sleeve assembly 136 having a passagewaybetween the first end 131 and the second end 132 it also includes one ormore connector sleeve orientation features. Connector sleeve orientationfeatures can have many different suitable constructions such as lugs,tabs, openings, etc. for cooperating with the one or more couplinghousing orientation features on the female coupling housing. In theembodiment illustrated and best shown in FIG. 7, the housing 133 ofconnector sleeve assembly 136 includes a first lug 136 b and a secondlug 136 c for fitting the connector sleeve assembly 136 into the femalecoupling housing 164. Stated another way, connector sleeve assembly 136fits into female coupling housing 164 in only one orientation usingfirst tab 136 b and second tab 136 c having different shapes asdiscussed below.

Connector 100 may also include a cable adapter 180 for easily allowingthe use of different sizes or types of cables 140 with the connector100. Cable adapter 180 is sized to fit within a rear opening of femalecoupling housing 164 and size the passageway for the particular cabledesired for use with the connector 100. By way of explanation, if adifferent size or type of cable is desired for use with connector 100the substitution of the correctly sized cable adapter may be the onlypart that requires changing for the use of the cable. Cable adapter 180may be secured with an adhesive, friction fit, threads or the like.

FIG. 16 is an end perspective view of the cable assembly 200 showingconnector 100 with the dust cap removed. Female coupling housing 164 ofconnector 100 may have any suitable construction for the fiber opticconnector using the concepts disclosed herein. The female couplinghousing 164 is sized for receiving the male plug connector 5 within thefront end opening for direct optical mating. Fiber optic connector 100has a relatively small form factor and aligns the plug connector 5 inthe proper orientation so it may only mates in one direction. Further,the optical coupling between the connector 100 and the plug connector 5is environmentally sealed. Additionally, fiber optic connector 100 maybe optically coupled and uncoupled with plug connector 5 as desired.

As best shown in FIG. 16, female coupling housing 164 has an elongatestructure with a passageway 163 extending from the opening at a frontend 161 to a rear end 162 and sized so that the shroud of the plugconnector 5 fits into the front end 161 of passageway 163 when properlyaligned. Consequently, plug connector 5 may be directly mated with thefiber optic connector 100 for making an optical connection therebetween.As shown, female coupling housing 164 includes a first portion at thefront end that includes the internal attachment feature such as internalthreads 165 that cooperate directly with the complimentary externalthreads of plug connector 5. Once the plug connector 5 is attached tothe fiber optic connector 100 the assembly is suitable for making anoptical connection therebetween.

Female coupling housing 164 includes features for aligning and securingconnector sleeve assembly 136 along with alignment features forcorrectly orientating plug connector 5. In one embodiment, femalecoupling housing 164 includes a stop ledge 164 a integrally formed in aside wall (i.e., disposed on the side wall) that is disposed rearward ofinternal threads 165. Stop ledge 164 a is configured so that it onlyallows the shroud of plug connector 5 to fully seat within the femalecoupling housing 164 in one orientation for keying the optical coupling.In other words, the shroud of the plug connector 5 has alignment fingershaving different shapes and the stop ledge 164 a only allows the plugconnector 5 to fully seat for optical coupling in one orientation bypreventing insertion of the larger alignment finger into the femalecoupling housing 164 past the stop ledge 164 a. Female coupling housing164 also includes a shelf (not visible) within the passageway anddisposed rearward of the stop ledge 164 a. Shelf 164 d has acomplementary shape for receiving connector sleeve assembly 136 andincludes a first retention feature 164 b and a second retention feature164 c. First retention feature 164 b and second retention feature 164 chave different sizes that cooperate with tabs 136 b, 136 c disposed onconnector sleeve assembly 136 so that it may only fully seat into thefemale coupling housing 164 in one orientation. Further, the stop ledge164 a has a specific orientation relative to first retention feature 164b and second retention feature 164 c.

When fully assembled the body 155 fits into female coupling housing 164and is keyed to direct the insertion of the same into the couplinghousing 164 in the correct orientation. In this case, shells 155 ainclude planar surfaces on opposite sides of body 155 to inhibitrelative rotation between body 155 and female coupling housing 164. Inother embodiments, the body 155 may be keyed to the female couplinghousing 164 using other configurations such as a complementaryprotrusion/groove or the like.

The rear end of housing 164 includes second portion (not numbered)having a reduced cross-section. The second portion is used for securingheat shrink tubing 167 (the heat shrink tubing is depicted in the shrunkform in FIG. 5) for providing environmental protection between thehousing 164 and the fiber optic cable 140 and weatherproofing the cableassembly. The other end of heat shrink tubing 167 is disposed about aportion of the cable, thereby inhibiting water from entering connector100. Further, the second portion allows for the attachment of boot 166to the rear end of the female coupling housing 164. After the heatshrink tubing 167 is attached, boot 166 may be slid over heat shrinktubing 167. Specifically, boot 166 may be positioned over the shrinktubing 167 at rear end 162 of female coupling housing 164 for providingfurther bending strain relief for the cable assembly.

Boot 166 may be formed from a flexible material such as KRAYTON or thelike. Heat shrink tubing 167 and boot 166 generally inhibit kinking andprovide bending strain relief to the cable 140 near connector 100. Boot166 has a longitudinal passageway (not visible) and may have a steppedprofile therethrough. The first end of the boot passageway is sized tofit over the heat shrink tubing 167. The first end of the bootpassageway has a stepped down portion sized for cable 140 or othersuitable cable that may be used and the heat shrink tubing 167 and actsas stop for indicating that the boot is fully seated. Dust cap 168 hasexternal threads for engaging the internal threads of female couplinghousing 164 for attachment and thereby inhibit dirt and debris fromentering the connector 100 via the front end 161 of female couplinghousing 164. Moreover, the dust cap 168 may include an O-ring forproviding a weatherproof seal between fiber optic connector 100 and dustcap 168 when installed.

FIG. 17 is a perspective view of the cable assembly 200 being alignedwith a complimentary plug connector 5 for mating. As shown, the shroudof the male plug connector 5 has alignment fingers having differentshapes and when mated the female coupling housing only allows the plugconnector 5 to fully seat for optical coupling in one orientation bypreventing insertion of the larger alignment finger into the femalecoupling housing 164 past the stop ledge. In one embodiment, the correctmating orientation is marked on the female coupling housing 164 such asan alignment indicia so that the craftsman can quickly and easily mateconnector 100 with the plug connector 5. For instance, the alignmentindicia may be an arrow or dot molded into the female coupling housing164, however, other suitable indicia may be used. Thereafter, thecraftsman engages the internal attachment feature 165 such as internalthreads of female coupling housing 164 with the complimentary externalthreads of plug connector 5 for making the optical connection.

Additionally, the optical connection is easily connected or disconnectedby merely mating or unmating the plug connector 5 with the fiber opticconnector 100 by threadly engaging or disengaging the coupling nut onthe plug connector 5 with the attachment features 165 such as internalthreads of the female coupling housing 164 of the fiber optic connector100.

FIGS. 18-20 depict views of another connector 300 with a constructionthat inhibits excess displacement of the ferrule relative to the ferrulesleeve. FIG. 18 depicts an exploded view of connector 300 and FIGS. 19and 20 respectively are an exploded view and a perspective assembledview of a sub-assembly 380 of connector 300. Connector 300 is asimplified connector design comprising a ferrule assembly 352 having aferrule 352 b and a ferrule holder 352 f, a resilient member 352 c, abody 355, and a connector sleeve assembly 336 comprising a housing 333and a ferrule sleeve 335. In this connector 300, the body 355 acts bothas a spring push for the ferrule assembly 352 and a cable strain reliefat the rear portion. Consequently, body 355 has a passageway 355P forreceiving a portion of the ferrule assembly therein when assembled.Other components of connector 300 such as the crimp band 170, femalecoupling housing 164, cable adapter 180, and boot 166 are similar tocomponents of other connectors disclosed herein and will not bediscussed in detail for the sake of brevity.

The design of connector 300 limits excess travel of the ferrule 352 b byhaving an extended length ferrule sleeve 335 that inhibits longitudinaldisplacement within the housing 333 of the connector sleeve assembly 336by being configured to have an insertion stop at the front end of theferrule holder 352 f As used herein with this embodiment, “inhibitedfrom longitudinal displacement” means that the ferrule sleeve 335 istrapped in the passageway of the housing 333 and the of the front end ofthe ferrule holder 352 f and may only move a suitable distance in theaxial direction therein while inhibiting over-travel of the ferrule intothe ferrule sleeve. For instance, the ferrule sleeve may only be allowedto move as distance such as a 100 microns or less when assembled intosub-assembly 380, but other suitable axial displacement lengths arepossible. Compared with embodiments using connector assembly 52 and allother things being the same, the ferrule sleeve of connector 300 has alonger length than the ferrule sleeves used with conventional connectorshaving connector assembly 52 since the housing of the connector is notthe stop surface.

Ferrule holder 352 f may be keyed with body 355 and biased forward byresilient member 352 c. Further, ferrule holder 352 f may cooperate withbody 355 to have multiple insertion positions for tuning. Housing 333 isconfigured for attaching to body 355 using one or more protrusions (notnumbered) on the body 355 that cooperate with features on the housing333 such as depicted in FIG. 20. Consequently, sub-assembly 380 has asimplified design with fewer components. Body 355 may be shaped to keywith female coupling member 164 such as having a portion with a D-shapedsection so it only is fully-seated in one orientation.

Although the disclosure has been illustrated and described herein withreference to explanatory embodiments and specific examples thereof, itwill be readily apparent to those of ordinary skill in the art thatother embodiments and examples can perform similar functions and/orachieve like results. All such equivalent embodiments and examples arewithin the spirit and scope of the disclosure and are intended to becovered by the appended claims. It will also be apparent to thoseskilled in the art that various modifications and variations can be madeto the concepts disclosed without departing from the spirit and scope ofthe same. Thus, it is intended that the present application cover themodifications and variations provided they come within the scope of theappended claims and their equivalents.

We claim:
 1. A fiber optic connector, comprising: a connector assemblycomprising a housing, a ferrule, a ferrule holder and a resilient memberfor biasing the ferrule and the ferrule holder forward; a ferruleinsertion stop being a collar disposed about a portion of the ferrule,wherein the collar is disposed forward of the ferrule holder; a firstshell and a second shell for securing the connector assembly at a frontend of the shells; a connector sleeve assembly comprising a housingcomprising one or more features configured for attaching to theconnector assembly and a passageway between a first end and a secondend, and a ferrule sleeve, wherein the ferrule of the connector assemblyis at least partially disposed in the ferrule sleeve when assembled; anda female coupling housing comprising an opening for receiving acomplimentary connector.
 2. The fiber optic connector of claim 1, thehousing of the connector sleeve assembly further comprising one or moreconnector sleeve orientation features that cooperate with one or morefemale coupling housing orientation features.
 3. The fiber opticconnector of claim 1, wherein the housing of the connector sleeveassembly comprises one or more latch arms for attaching to a portion ofthe housing of the connector assembly.
 4. The fiber optic connector ofclaim 1, further comprising a crimp band.
 5. The fiber optic connectorof claim 1, the connector assembly being an SC connector assembly. 6.The fiber optic connector of claim 1 being a portion of a cable assemblyfurther comprising a fiber optic cable attached to the fiber opticconnector.
 7. The fiber optic connector of claim 1, wherein a length ofthe collar is sized so that when it abuts the ferrule holder apredetermined length of the ferrule is exposed.
 8. A fiber opticconnector, comprising: a connector assembly comprising a housing, aferrule, a ferrule holder and a resilient member for biasing the ferruleforward; a ferrule insertion stop disposed about a portion of theferrule, wherein the ferrule insertion stop is a collar disposed about aportion of the ferrule, wherein the collar is disposed forward of theferrule holder; a first shell and a second shell for securing theconnector assembly at a front end of the shells; a connector sleeveassembly comprising a housing comprising one or more features configuredfor attaching to the connector assembly and a passageway between a firstend and a second end, and a ferrule sleeve, wherein the ferrule of theconnector assembly is at least partially disposed in the ferrule sleevewhen assembled; and a female coupling housing comprising an opening forreceiving a complimentary connector.
 9. The fiber optic connector ofclaim 8, the housing of the connector sleeve assembly further comprisingone or more connector sleeve orientation features that cooperate withone or more female coupling housing orientation features.
 10. The fiberoptic connector of claim 8, wherein the housing of the connector sleeveassembly comprises one or more latch arms for attaching to a portion ofthe housing of the connector assembly.
 11. The fiber optic connector ofclaim 8, further comprising a crimp band.
 12. The fiber optic connectorof claim 8, the connector assembly being an SC connector assembly. 13.The fiber optic connector of claim 8 being a portion of a cable assemblyfurther comprising a fiber optic cable attached to the fiber opticconnector.
 14. The fiber optic connector of claim 8, wherein a length ofthe collar is sized so that when it abuts the ferrule holder apredetermined length of the ferrule is exposed.
 15. A fiber opticconnector, comprising: a connector assembly comprising a housing, aferrule, a ferrule holder and a resilient member for biasing the ferruleforward; a ferrule insertion stop disposed about a portion of theferrule, wherein the ferrule insertion stop is a collar disposed about aportion of the ferrule, wherein the collar is disposed forward of theferrule holder.
 16. The fiber optic connector of claim 15, wherein alength of the collar is sized so that when it abuts the ferrule holder apredetermined length of the ferrule is exposed.